1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing thereof which carries out ion implantation before a silicide process.
2. Description of the Background Art
A silicide process is typically carried out on respective electrodes, i.e., gate, source and drain of MISFETs (Metal Insulator Semiconductor Field Effect Transistors) formed on a semiconductor substrate, contact regions of other interconnects and the like for resistance reduction. Metal for use in such silicide process includes Co, Ni and the like.
For instance, “Suppression of Thermally Induced Leakage of NiSi-Silicided Shallow Junctions by Pre-Silicide Fluorine Implantation” (M. Tsuchiaki et al., Japanese Journal of Applied Physics, Vol. 44, No. 4A, 2005, pp. 1673-1681) reports that pre-silicide fluorine implantation into regions to be silicided achieves leakage suppression.
The above paper reports that the fluorine implantation into regions to be silicided is also effective for CMOS (Complementary MOS) fabrication, and achieves leakage suppression. Experiments conducted by the inventors of the present invention, however, have revealed that a leakage current rather increases in P-channel type MISFETs while the leakage suppression effect was indeed observed in N-channel type MISFETs.